Factory Energy Monitoring: Tracking kWh and CO₂ per Unit Produced

The electricity bill hides the real story

Most factories know their total monthly electricity cost. Very few know which machines use that energy, how much is spent while nothing is being produced, or how much energy goes into each unit they sell. With power prices high and export customers increasingly asking about carbon footprints, that gap is becoming expensive.

Measure per machine, not per building

A main meter tells you the total. Machine-level metering tells you where to act. Energy meters or current sensors on major loads such as motors, compressors, heaters and chillers show live power draw for each one, and combining that with production data turns energy into a production metric instead of an overhead.

Energy per unit is the number that matters

Energy intensity is simply the energy used divided by the good units produced over the same period. It is the fairest way to compare shifts, lines and products, because it accounts for output. A line that uses more electricity but produces far more good parts may actually be the most efficient one in the plant.

Linking energy to OEE makes this even clearer. When OEE drops, energy per unit usually rises, because machines keep drawing power through stops, slow running and rework.

Find the vampire loads

Idle machines are one of the easiest savings to find. Hydraulic packs, heaters, compressors and conveyors are often left running through breaks, changeovers and even between shifts. With per-machine monitoring, a system can flag a machine that is drawing significant power while producing nothing, so someone can switch it off or fix the shutdown routine.

Estimating Scope 2 emissions

Scope 2 emissions are the indirect emissions from the electricity you buy. The basic location-based calculation is electricity used in kWh multiplied by the grid emission factor for your region, in kg CO₂ per kWh. Do this per shift and divide by good units, and you get CO₂ per unit, a figure customers and auditors increasingly ask for.

Grid emission factors vary by country and over time, so use an up-to-date published factor for your grid, and keep a record of which factor you used for each report.

Cut peak-tariff costs

Many industrial tariffs charge more during peak hours. Once you can see energy use by machine and by hour, you can move flexible loads such as batch processes, charging or pre-heating into off-peak windows, and see the saving in the next report.

How we approach it

The energy module in EnicSoft OEE tracks live power per machine, detects idle loads automatically, calculates Scope 2 CO₂ per shift and per unit from grid emission factors, and analyses peak and off-peak costs, all alongside OEE. If you want to understand where your factory's energy really goes, start with your largest few machines and build from there.